Attempts have been made with various agents to reduce the development of tolerance and hyperalgesia following remifentanil. Postoperative hyperalgesia and its prevention has been studied with ketamine , Magnesium , Gabapentin, Clonidine, Lornoxicam , Dextromethorphan , Paracetamol , Morphine , Dexmedetomidine , Adenosine, COX inhibitors , Amantadine , Nitrous oxide, Fentanyl, Pregabalin , Buprenorphine, Midazolam, Dexamethasone. Relevant to our current hypothesis is the report that concomitant administration of ultra-low dose naloxone and naltrexone with remifentanil prevented OIH. However, there are no studies on reducing the adverse effects of remifentanil with ultra-low dose naloxone in human subjects.